Connecter



y 30, c. A. ROWLEY 1,911,395

CONNECTER Filed Jan. 5, 1951 ATTOR 35- 3 Chafle jl su l y Patented May 30, 1933 UNITED STATES PATENT OFFICE CHARLES A. ROWLEY, F BLOOIVIFIELD, NEW JERSEY, ASSIGlQiOR TO THE RAJAH CONE- PANY, 0F BLOOMFIELD, NEW JERSEY, A CORPORATION OF NEW YORK CONNECTER Application. filed January 5, 1931. Serial No. 506,569.

This invention relates to a connecter for electrical circuit elements and particularly to a connecter adapted to be locked in place so as to prevent its separation except by a manipulation which is substantially impossible of accidental accomplishment.

A great many and varied types of connecters have been proposed and used prior to my invention for making and holding a satisfactory electrical contact and mechanical connection between separable elements of an electrical circuit. For many uses the problem is not a particularly difficult one and many of the types of connections heretofore known have proved inexpensive to manufacture and satisfactory in operation. For certain purposes, however, the problem hasnot been solved. One of the most exacting of such uses is the connection of ignition wires to spark plugs and distributors, etc. OifiiLVliL- tion engines. The connection is Sub ected to severe vibration and to repeated connection and disconnection which try to the limit the ability of the connection to hold under all circumstances. In aviation engines, in particular. the circuit must be maintained, since a break may often means the wrecking of an expensive ship and frequently the loss of life as well. In View of this situation, repeated efforts have been made to provide some locking means which would be secure against disengagement by any accidental means and yet which could be quickly connected or disconnected during repair and /or inspection operations. Of these none has been so satisfactory as to entirely meet the scrupulous demands of aviation.

Inthe co-pending application of George H. E. Berthold and myself, Serial Number 466,438, filed July 8, 1930, is disclosed one type of locking connection which has proved more secure against accidental displacement than any other heretofore known. This type of terminal, however, fails to entirely meet the requirements of every case since it is necessarily a radial connection and occupies a considerable space, whereas in the design of many motors and particularly of radial motors, a more compact and more flexible connection is desired sincethe space about the V spark plughead is extremely limited;

Accordingly, it is an objectof the present invention to provide a connection which will be absolutely secure against accidental disconnection, which will be compact and occupy a minimum of space and which will be flexible, permitting the wire or other circuitelement to approach the spark plug (or other element) at almost any desired angle.

In. the accompanying drawing in which I have shown a preferred embodiment of my invention r l Fig. 1 shows in perspective the connection made but not yet locked; l

Fig. S2 is a view at right angles toFig. 1, showing the connection after it is locked;

Fig. 3 is a view partially in longitudinal section taken on line 33 of Fig. 1, showing the method of makingo-rbreaking the connection;

Fig. 4; is a section on line 4-4 of Fig. 3;

i Fig. 5 is a similar sectionshowing the connection after it is locked; and

Fig. 6 is a View in perspective showing the several parts ready forassembling.

I have shown in the drawing the upper portion of a spark plug 10 having a. vball terminal 11. The contact element of the connection consists of a common type of spring fork 12 shown best in Fig. 6. This fork has prongs 18, each of whichjs formed with a spherical depression 14 adapted .to embrace the spherical face of the ball terminal 11. The ends of theseprongs 13 are formed as shown at 15 witha flared lip adapted to act as a cam against the spherical face I ,of the ball terminal 11 to spread the spring.

fork 12 when the fork is pushed over the ball terminal. The spring contact fork 12 is connected to the insulated conductor 16 in the usual way and in the preferred embodiment is also connected to an insulating ferrule 17 adapted to take the push and pull required for making and separating the contact and thus to relieve the strain from the conductor. I

The contact as thus described is not essentially different from connecters which have been known and used for a number of years for connecting spark plug wires and aviation engines. According to my invention, however, the contact once made is mechanically secured so that it cannot be separated Without a special manipulation incapable of accidental occurence. In order to effect this result a metal sleeve 20 is secured over the spring contact fork 12 so that it substantially fits theoutside of the spring fork 12 When it isclosed This fit is sufficiently close so that when the sleeve embraces the fork 12 it will not tolerate the separation of the prongs 13 sufficiently to permit theball terminal to leave the spherical depressions 14.

The sleeve 20 in the present embodiment of the invention is secured in position over the spring contact fork 12 by means of a locking spring 21. Prongs 22 on opposite sides of'locking spring 21 fit into corresponding holes 23 near the base of the prongs 13 and extend therethrough a distance suflicient to permit their engagement in the annular groove 24 near the top of the sleeve 20. The end 25 of the spring 21 is also formed so that it extends beyond the side of the prong 13 and forms a latch engaging in the longitu dinalgroove 26 of the sleeve 20, as shown most clearly in Figs. 4 and 5. The several parts as shown in Fig. 6, are thus assembled by inserting the spring 21 between the prongs 13 with its prongs 22 extending through the holes 23. The sleeve 20 is then pushed'over the end of the contact fork 12 and the spring 21 is contracted sufficiently to permit the prongs 22 to enter the sleeve 20 and engage in the groove 24.

In using the connection of my invention the sleeve 20 is turned as shown in Figures 1, 3 and 4 so-tha-t its opening 30 is aligned w-ith'one of the prongs 13. In this position the latch 25 will be engaged as shown in Fig. 4'inoneofthe four equally spaced longitud= ina l grooves 26. With the sleeve in this position the connecter is pushed over the end of the ball terminal and as shown in Fig. 3 the pron-g 13' will be permitted to spring outwardly intothe-opening 30, thus allowing the terminal to enter between the prongs 13- and be received in the spherical depressions14, Once the terminal has reached the spherical depress-ions 14 the prong 13 springs backto its original position and the sleeve 20 may betu-rned 90 to the position indi-' catedgin-Figures 2 and 5. In this position uncut portions of the sleeve are behind the prongs 13 and serve to limit their outward movement soas to prevent their springing apart sufiicientlyto permit the ball termimil to leave the spherical depressions 14. In this position the connection is absolutely secure and cannot be separated except by such force as to destroy the connecter itself. Nevertheless, the connection is entirely flexlble, perm tting the conductor to be bent "down at right angles to the plug in any direction or to be placed at anyintermediate angle. The sleeve 20 is held in this looking position by the latch 25 which is engaged in a slot 26 as shown in Fig. 5.

To separate the connection, it is only necessary to turn the sleeve 20 once more through 90 and then to pull the connecter from the ball terminal. In this position one of the prongs 13 being aligned with the opening 30 is free to flex outwardly, and thus the prongs may be separated suficiently to allow the withdrawal of the male terminal without substantial difficulty.

Although I have shown in the drawing and described above one embodiment of my invention, it will be understood that many changes and modifications thereof may' be made without departing from the scope of my invention as claimed herein. Thus, instead of cutting away a portion of the sleeve, its interior may be shaped so as to be sufficiently wider'on one diameter than on another so that the sleeve in one position will prevent the separation of the prongs 13 and in another position will permit sufficient separation to allow the male terminal to be introducedor Withdrawn. Such arrangements are, however, less advantageous than that shown in the drawing. .1. In particular, the provision of an opening 30 allows greater flexibility between the male and female terminal-s permitting them to be swung to an angle of 90 or less with the axis of the male terminal, which would not be possible if the openings were not provided. r I

Furthermore, when the male and female terminals are'at an angle to each other, the neck of the male terminal engaging in the opening 30 serves asan additional'lock to prevent any possibility of the sleeve being turned so as to permit accidental separation.

Other forms of female contacts may be used instead of the prongs 13 as illustrated. It is desirable, however, to have the contact between the sleeve and the back ofthe female terminal such that a force against the female contacts will not tend to move the locking sleeve to its disengaged position, otherwise the locking sleeveitself should be positively latched against accidental movement.

I am aware; that prior to my invention it has been suggested to make connecters with female jaws which were to be closed over the male terminal by a longitudinal movable member acting upon the jaws by a cam action, e. g.., against angular faces. As intimated above, such movable members do not constitute a satisfactory locking sleeve since the cam action is reversible and under an accidental stress may serve to release. the jaws of the female terminal. Nor is this defect cured by the use of a sleeve moved lon itudinally over the cam faces of the femi lle jaws by means of a screw thread. The

threads tend to hold the sleeve against direct reversing of the cam action but, as is well known, screws are peculiarly subject to movement under vibration so that the female jaws maybe entirely released merely by the vibration of the motor in operation.

The present invention is in contrast to these prior suggestions in that it contemplates limiting the contact jaws rigidly to prevent withdrawal from the male terminal, and holding the limiting means in its locking position positively, as distinguished from any mere frictional engagement, e. g., as in the case of a screw thread.

WVhatever form of female contacts are used,

it is to be understood that they should have longitudinally concave faces so as to require minal. By concave I do not intend to suggest a limitation to a smooth or continuous curve since obviously the concavity could be angular without seriously impairing its function, or can be merely a hole which would accommodate the convexity of the male terminal.

Again, instead of using the locking spring 21 other means may be used for securing the sleeve rotatably to the female terminal and/or for holdin the sleeve in its locking position. Thus, or example, an integral prong could be pressed out from the female terminal into the groove 24 so as to hold the sleeve against removal and the edges of the prongs 13 could serve with a shallow longitudinal groove in the sleeve to latch the sleeve in its limiting position. These and many other changes may be made without departing from the scope of the invention claimed herein.

What is claimed as new is:

1. A connecter comprising a male terminal longitudinally convex in the direction of engagement, and a female terminal having separable prongs concave to embrace said convex part and engage therewith, a sleeve rotatably mounted over said prongs having one side cut away to form an opening sufficiently large to permit one of said prongs to be moved outwardly into the opening when aligned therewith and having rigid portions adapted to be simultaneously positioned behind said prongs and to limit their separation.

2. A connecter as defined in claim 1 in which the male terminal is a ball terminal and the opening in the limiting sleeve is adapted to receive the neck of the male terminal so as to permit unobstructed angular movement between the male and female terminals when locked.

3. A detachable connecter comprising opposite resilient prongs, each having a depression near its free end, a rigid sleeve rotatably secured over said prongs and having an opening in one side sufficient to permit one prong to be bent out into said openthe prongs.

1. A connecter as defined in claim 3, in which means for holding the sleeve in one position comprises a latch spring mounted between said prongs having a portion adapted to engage longitudinal grooves on the inside of the sleeve and having projections extending through said prongs and engaging an annular groove in said sleeve so as to hold it rotatably over said prongs.

Signed at Bloomfield, N. J., this 11th day of December, 1930. separation on withdrawal from the male ter- CHARLES A. RQWLEY. 

